Quizzes.Next Linking stimuli and questions in the Q bank

I'm a Spanish teacher, trying to create a listening quiz using quizzes.next. What I want to happen is that I have 15 stimuli (in this case, listening samples) and I want to attach 1 question to each stimuli.

But I want the quiz to pull 5 stimuli/questions for the quiz.

When I try to add things to the bank, I can only add the stimuli and the question does not stay linked.